api/middleware.py

"""
middleware.py
=============
FastAPI middleware for request timing and CORS.
"""

import logging
import time

from fastapi import Request
from starlette.middleware.base import BaseHTTPMiddleware

logger = logging.getLogger(__name__)


class TimingMiddleware(BaseHTTPMiddleware):
    """
    Middleware that logs request latency and adds X-Process-Time header.
    """

    async def dispatch(self, request: Request, call_next):
        start = time.perf_counter()

        response = await call_next(request)

        elapsed_ms = (time.perf_counter() - start) * 1000
        response.headers["X-Process-Time"] = f"{elapsed_ms:.2f}ms"

        # Log request info
        logger.info(
            f"{request.method} {request.url.path} — "
            f"{response.status_code} — {elapsed_ms:.2f}ms"
        )

        return response